permission issues

Please pardon this potentially noob question but it's been several months since I installed and configured Apache/PHP and I have someone setting up a web site and having problems. Maybe someone can help with a quick answer.. I'm running Apache with mod PHP and have php running in safe-mode. I am under the impression that this will still allow the user the ability to write/create files in their area as long as the UID/permissions match. However, I'm getting "permission denied" when trying to do so with fopen/fwrite mode "w" trying to create a file in a directory owned by the same owner as the file. Any ideas what's wrong? I have tried making the directory 777, it doesn't help; I've tried creating the file already and making it 777 and that doesn't help. I went through my php.ini file and can't find any flag that is restricting the use of fwrite/fopen but I'm not sure if I've checked all the config files. If there is some restriction in effect, can I disable it on a domain-by-domain basis? Can I still keep safe mode on? Is this something I should do within Apache's configuration, or locate local versions of php.ini somewhere? Thanks for any advice!